This invention relates to disinfecting lenses, such as contact lenses. In particular, the invention relates to apparatus useful to quickly and effectively disinfect lenses while reducing eye irritation caused by disinfecting the lenses.
Contact lenses should be periodically disinfected to protect the wearer's eyes from infection and to improve the wearer's comfort. It is often desirable that contact lens disinfecting be accomplished quickly, e.g., for the convenience of the wearer. However, conventional fast-acting disinfectants that are used with contact lenses have a high potential to cause eye irritation. In fact, the general rule has been that the amount of eye irritation to be expected is directly proportional to the rate of disinfecting. Fast-acting disinfectants, such as hydrogen peroxide, cause significant ocular irritation if placed directly in the eye. Thus, when using such disinfectants a thorough rinsing and/or neutralization step is often required to remove substantially all traces of the disinfectant. Also, such disinfectants are often not stable and tend to lose their potency over time. A fast-acting, stable contact lens disinfecting system which is not as prone to cause eye irritation would clearly be advantageous.
Gaglia, Jr. U.S. Pat. No. 3,912,451 discloses using a platinum group metal as a hydrogen peroxide decomposition catalyst. This patent discloses that the platinum group metal is supported on a substrate by electrolytic deposition or by coating a substrate with an oxidized platinum group metal component in a liquid carrier and then reducing the oxidized platinum group metal component. Although the platinum group metal component is initially effective to promote the decomposition of hydrogen peroxide, over a relatively short period of time the substrate becomes ineffective. It is believed that the platinum group metal component is lost from the substrate is lost from the substrate.
The use of chlorine dioxide dissolved in an aqueous liquid medium to disinfect substrates, such as contact lenses, has previously been suggested. One problem with such disinfection methods is that chlorine dioxide has relatively limited solubility/stability in water so that a chlorine dioxide/water solution prepared well in advance of its use loses its chlorine dioxide and become ineffective as a disinfectant. One approach to overcoming this problem is to use a liquid medium containing a chlorine dioxide precursor, such as stabilized chlorine dioxide.
It would be advantageous to rapidly and effectively generate a contact lens disinfecting amount of chlorine dioxide from a chlorine dioxide precursor.